Because there is no proof of God, it stands to reason that many believers would in fact like there to be some proof that God does exist, that He is actively taking an interest in their lives. Surely the murder of innocents - aka abortion - is so evil that He must want to stop it. Therefore, if we could only stop abortion, that would prove that there is a God because He was at the very least able to stop one outrageously evil thing from happening in this fallen world.
But of course there is no God. Still, if our government only resembled the imaginary theocracy we all inherently desire, then at least we would have proof of God in the form of a Godly government, a government that outlaws everything contrary to His law. In a theocracy, you can be certain that God exists because He has been instantiated in the form of anti-abortion laws, the mutaween, or whatever particular variant you are currently enjoying. You'll sleep better at night knowing that God exists because He is actively preventing you from doing things you know you shouldn't be doing (coveting your neighbor's wife or what have you) and preventing your neighbors from doing things you know they shouldn't be doing (like teh buttseks).